Dry Rot and Other Wood-Destroying Fungi: Their Occurrence, Biology, Pathology and Control

Microbial biodeterioration of building materials and their contents in both modern and historic buildings is attributed to changes in the building environment. The main environmental parameters favouring the decay of materials and contents are water, humidity, temperature and lack of ventilation. The damage caused by biological agents is very familiar, as is the destruction arising from attempts to eradicate them by the use of chemicals, which not only are a cause for concern to health authorities, wildlife interests and environmentalists, but also lead to the development of resistance in the target organisms. Correct identification of the deteriogen material is important as not all deteriogens are equally destructive. Some rots and insects are present in timber when it is cut, or are acquired in storage, and these may be present in heartwood or sapwood. Fungal or insect infestation may also be dead or dormant, representing conditions in the past. Environmental control and preventative maintenance are preferable to chemical means. Buildings work as spatial environmental systems and must be understood as a whole. They separate the occupants from the external environment, thus creating a different internal environment for the occupants. The causes of decay in materials and structures are influenced by the internal building environment which has a varied microclimate depending upon structural aspects of the building. Preventative maintenance should in most cases forestall the need for major interventions, and it is beyond doubt that it reduces the cost of the conservation of buildings. Since the internal environment of a building is the product of a number of influences, it is advisable to study in detail the ecological factors such as temperature, humidity at the micro-environment levels and the response and performance of the building before undertaking an intervention involving any building. Continuous monitoring of the environment in buildings ensures the long-term health of both building materials and overall structures.